I missed that. It certainly wasn't clear to me from the rest of the post that the author realized they were talking about a cache. Possibly because I'd be temp

I missed that. It certainly wasn't clear to me from the rest of the post that the author realized they were talking about a cache. Possibly because I'd be tempted to make that the focus, since I consider "by the way we just re-invented the cache by accident!" to be an excellent climax-twist on a post like this. You think it's about this cool new data structure, but then it's actually about thinking from the ground up or about reasoning from multiple perspectives.